Sensor: Acceleration (without g)
The experiment "Acceleration (without g)" just gives the raw data from the phone's (typically virtual) accelerometer.
Note, that there is a possibly confusing distinction between "Acceleration with g" and "Acceleration (without g)". Typically, the sensor in your phone is a very tiny mechanical system (known as MEMS, "microelectromechanical system"), that measures the gravitational acceleration as a force acting on a sample mass. Therefore, this sensor will report the earth's acceleration of 9.81 m/s² while the phone is resting (which is what we call "Acceleration with g"). In contrast, the physical acceleration is zero when the phone is resting (or moving at a constant speed), so there is a virtual sensor which subtracts the constant acceleration (usually by taking into account the data from other sensors as well). This is what we call "Acceleration (without g)" and it will actually report an acceleration of zero while the phone is not accelerated.